A conjugated diene polymer (e.g., styrene-butadiene rubber and nitrile rubber) is used as a raw material for producing a rubber product (e.g., tire).
In particular, a conjugated diene polymer that includes a halogen atom at the terminal of the polymer chain is useful as an intermediate for producing a rubber product since the desired functional group or the like can be introduced into the terminal of the polymer chain so as to substitute the halogen atom.
It is possible to produce a rubber product having higher performance by stably producing a conjugated diene polymer having a specific molecular weight and a narrow molecular weight distribution.
A method that utilizes a living radical polymerization method is known as a method for producing a conjugated diene polymer that includes a halogen atom at the terminal of the polymer chain, and has a narrow molecular weight distribution.
For example, Patent Literature 1 discloses a method that produces a conjugated diene polymer by polymerizing a conjugated diene monomer and the like by means of a living radical polymerization method using a specific ruthenium complex and an organic halide.